1. 
A sealed steel container of methane gas is slowly heated. The temperature increases by 5C every 15 minutes. If the initial temperature was 25C, what will the initial to final temperature ratio (T_{i}/T_{f}) be after three hours?


2. 
The gravitational attraction between two objects is given by the formula F= G(m_{1}m_{2}/d^{2}) where m represents the masses of the two objects, d is the distance between them and G is the gravitational constant (note: G = 6.67 x 10^{11}m^{3}kg^{1}s^{2}). (a) Calculate the gravitational force between two objects (m_{1} = 495,000 kg, m_{2} = 1,470,000 kg) that are separated by 90 meters. (b) Then determine what the force is if m_{1} is doubled and d is decreased by a factor of 1/4 (hint: calculate what to subtract first and then subtract from d; do not just multiply d by the fraction).


3. 
If the ratio of difficult physics problems to easy physics problems in a book is 2 to 4, how many easy problems are there if there are 380 problems in the book? Round your answer to the nearest whole number if necessary.


4. 
Brianna dropped rock 1 (mass = 2.8 kg) from a height of 13 meters. She then dropped rock 2 (mass = 0.8 kg) from the same height. What was the ratio of kinetic energies of the rocks (KE_{rock1}/KE_{rock2}) when they hit the ground? (note: the acceleration of gravity is 9.81 m/s^{2}.)


5. 
* This is a premade sheet. Use the link at the top of the page for a printable page. 

6. 
On planet X, the atmospheric pressure is lower than it is on planet Y. Interplanetary probes were recently sent to the two planets and data were obtained on many things including the atmospheric pressure. The pressure on planet Y is 19 N/m^{2}. If the pressure on planet X is half that of planet Y, what is the pressure, in Pascals, on planet X? Round your answer to the nearest hundredth if necessary.

